盐胁迫对四照花形态解剖结构和渗透调节的影响毕业论文_林学毕业论文

盐胁迫对四照花形态解剖结构和渗透调节的影响毕业论文

2021-04-19更新

摘 要

[材料]以北美引进的落叶树种大花四照花(Cornus florida, CF)和乡土常绿树种秀丽四照花(Cornus hongkongensis subsp. elegans, CE)的一年生幼苗为试验研究材料。[方法]用海盐配制5个盐浓度梯度(0(CK)、2‰、3‰、4‰、4.5‰)的1/2Hogland进行水培处理,期间观察其存活情况,观测幼苗的器官解剖结构以及测定渗透调节物质(可溶性糖、可溶性蛋白、脯氨酸)含量。[结果] 本研究表明:(1)各处理的半活期分别为:CE(CK:gt;30 d,2‰:30 d,3‰、4‰:20 d,4.5‰:10 d);CF(CK:gt;20 d,2‰、3‰、4‰:20 d,4.5‰:10 d)。从中可以发现,四照花总体耐盐性较低,半活期较短;与CF相比,CE的耐盐性稍好,在2‰盐浓度下半活期可达30 d;(2)低浓度盐胁迫下增加了CE和CF根直径、皮层厚度,而高浓度盐胁迫降低了CE和CF根直径和皮层厚度;(3)CE和CF的茎直径、髓宽度、木质部、韧皮部和周皮厚度在低浓度盐胁迫下增加,而在高浓度盐胁迫下减小;(4)盐胁迫处理增加了CE和CF的叶片、栅栏组织和海绵组织的厚度;(5)脯氨酸(Pro)和可溶性糖含量均随着盐浓度的增加和胁迫时间的延长而上升,而可溶性蛋白含量呈先升后降的趋势。本研究推测:2‰低浓度盐处理下,可溶性蛋白含量的增加是两种四照花渗透调节的主要方式,而4.5‰高浓度盐处理下,大量积累Pro和可溶性糖是其主要渗透调节方式。渗透调节物质的大量积累可能是CF叶片膜系统稳定性较高的原因之一。[结论]低浓度盐胁迫对四照花器官解剖结构对低浓度盐胁迫有较好的响应机制,而高浓度盐胁迫则破坏了CE和CF的根、茎、叶的解剖结构,因此导致两种四照花的半活期降低;两种四照花均可通过增加脯氨酸、可溶性糖及可溶性蛋白含量来提高幼苗对盐胁迫的耐受性。

关键词:盐胁迫;秀丽四照花,大花四照花;种子萌发;生化指标

Effects of Salt Stress on Anatomical Structure and Osmotic Regulation Two Species in Cornus

ABSTRACT

[Material] The annual seedlings of deciduous species Cornus Florida (CF) introduced from North America and native evergreen species Cornus hongkongensis subsp. elegans (CE) were studied. [Method] 1/2 Hogland of 5 salt concentration gradients (0(CK)、2‰、3‰、4‰、4.5‰) was prepared with sea salt for hydroponic treatment. The survival of seedlings was observed, the organ anatomical structure of seedlings was observed, and the content of osmotic regulators (soluble sugar, soluble protein, proline) was determined. [Result] The results showed that: (1) CE(CK:gt;30 d,2‰:30 d,3‰、4‰:20 d,4.5‰:10 d);CF(CK:gt;20 d,2‰、3‰、4‰:20 d,4.5‰:10 d). It can be found that the overall salt tolerance of Cornus is lower and its half-life is shorter; compared with CF, CE has a slightly better salt tolerance, with a half-life of 30 days at 2 salt concentration; (2) the root diameter and cortex thickness of CE and CF are increased under low salt stress, while the root diameter and cortex thickness of CE and CF are decreased under high salt stress; (3) the stem diameter, pith width, xylem and phloem of CE and CF are decreased. The thickness of periderm and periderm increased under low salt stress, but decreased under high salt stress; (4) The thickness of leaves, palisade tissue and sponge tissue increased under salt stress; (5) Pro and soluble sugar content increased with the increase of salt concentration and the extension of stress time, while soluble protein content increased first and then decreased. This study speculated that the accumulation of soluble protein was the main osmotic regulation mode of two species of Cornus under 2 low concentration salt treatment, while the accumulation of Pro and soluble sugar was the main osmotic regulation mode under 4.5 high concentration salt treatment. The accumulation of osmotic regulators may be one of the reasons for the high stability of CF leaf membrane system. [Conclusion] Low concentration salt stress has a better response mechanism to low concentration salt stress on the organ anatomical structure of Cornus, while high concentration salt stress destroys the root, stem and leaf anatomical structure of CE and CF, which results in the decrease of half-life of two kinds of Cornus. Both kinds of Cornus can increase the tolerance of seedlings to salt stress by increasing the contents of proline, soluble sugar and soluble protein. 。

Key worlds: salt stress; Cornus hongkongensis subsp. Elegans, Cornus florida; hydroponics; biochemical indicators

目 录

前 言 1

1 绪论 2

1.1 植物盐胁迫研究进展 2

1.1.1 盐胁迫概况 2

1.1.2 盐胁迫对植物结构形态的影响 2

1.1.3 盐胁迫对植物渗透调节物质的影响 3

1.2 四照花种质资源概况 4

1.2.1 分类系统 4

1.2.2 分布情况 4

1.2.3 应用价值 4

2 试验材料和研究方法 6

2.1 试验材料 6

2.2 试验设计 6

2.3 指标测定与方法 6

2.3.1 器官解剖结构观测 6

2.3.2 渗透调节物质含量测定 7

2.3.3数据处理 8

3 结果与分析 9

3.1 盐胁迫对四照花半存活期的影响 9

3.2 盐胁迫对四照花形态指标的影响 9

3.2.1 盐胁迫对根解剖结构的影响 9

3.2.2 盐胁迫对茎解剖结构的影响 10

3.2.3 盐胁迫对叶解剖结构的影响 11

3.3 盐胁迫对四照花渗透调节物质的影响 12

3.3.1 盐胁迫对脯氨酸(Pro)的影响 12

3.3.2 盐胁迫对可溶性糖的影响 13

3.3.3 盐胁迫对可溶性蛋白的影响 14

4 讨论与结论 16

4.1 盐胁迫对四照花形态解剖结构的影响 16

4.2 盐胁迫对四照花渗透调节物质的影响 16

致谢 18

参考文献 19

前 言

当前,全球已有超过6%的土地面积和大约30%的耕地面积受到土壤盐渍化和灌溉引起的次生盐渍化的影响。仅我国,就有大约36000 hm2的滨海盐土面积,并且随着全球变暖,气候干旱、降雨集中、海水侵浸等,滨海地区土壤盐渍化程度持续加深,使农林业可持续发展面临着严峻挑战。滨海盐土含盐量高,适生林木种类较少,特别是耐盐、常绿的观赏园艺类木本花卉更是奇缺,导致滨海地区生物多样性较少,生态系统脆弱。因此,选择具有一定的耐盐性和观赏利用价值的植物来进行引种栽植,会对滨海盐土地区的生态恢复和经济增长具有十分重要的意义。

四照花(Cornus)为山茱萸科(Cornaceae),常绿或落叶小乔木或灌木,该树种不但树姿优美,还是集彩花、彩果、彩叶于一身的彩色树种,其栽培种的色彩更为丰富,并且颜色还能随四季的变换而变化,是极具发展前景的园艺观赏栽培树种。不仅如此,四照花在森林生态系统中也发挥着良好的生态效益。因此,其栽培种目前已广泛分布于北美各地的庭园和道路旁。在近年,亚洲部分国家,如日本、韩国等已陆续对四照花进行引种与推广和培育,也取得了很好的效果。然而,中国作为东亚四照花野生种质资源主要分布的地区,还并未充分认识到其潜在的园艺观赏和利用价值。因此,有必要在我国对四照进行资源开发、引种和推广栽培,并进一步扩大我国木本花卉市场。

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